1. Technical Field
The present invention relates to passage barriers which serve to optionally open or block the passageway of a person or the passageway of a vehicle.
2. Discussion
An already known embodiment of such a passage barrier comprises a barrier element in form of an automatic sliding door that optionally opens or blocks a passageway by means of the passage barrier. In order to detect the presence of a person within the passageway of the passage barrier, this one can be equipped with a corresponding sensor technology. It is for example known to provide several light barriers along the passageway, the sending devices of which emit light beams that cross the passageway, which light beams are received by corresponding reception devices. If the light beam extending from a sending device towards a reception device is interrupted by a person, the input signal missing at the reception device will represent the presence of a person within the passage barrier, whereupon a corresponding evaluation unit will detect a person within the passage barrier. The use of several light barriers is advantageous in that both the position and the direction of movement of the person within the passageway of the passage barrier can be detected due to the fact which light beams will be interrupted in which order by the person that moves through the passage barrier. An essential drawback of such a sliding door design is however that this one requires a very large construction space due to the path of displacement of the sliding door, which is not desired for many practical applications.
An alternative embodiment of a known passage barrier comprises a barrier element that can be preferably swivelled automatically around a swivelling axis within a swivelling area, for example in form of a swinging door that optionally opens or blocks the passageway of the passage barrier. An important advantage of such passage barriers comprising swivelling barrier elements is that these ones require much less construction space in the direction of the width than the above described embodiment with a sliding door. The passage barrier comprising a swivelling barrier element can also be equipped with light barriers arranged along a passageway of the passage barrier in front of and behind the swivelling area, in order to detect the presence of a person in the passageway. However, the provision of light barriers within the swivelling area of the barrier element is problematic since these ones will be interrupted by the barrier element itself when it is swivelled, which is the reason why during the swivelling of the barrier element as well as when the barrier element is open it is not possible to know, based upon the output signals of the corresponding light barriers, whether a person is present in the swivelling area or not. Accordingly, an alternative sensor technology for detecting the presence of a person within the passageway of the passage barrier, such as for example a motion sensor or the like, will be preferably used for passage barriers comprising a swivelling barrier element. However, such sensors present the drawback that the precise position of a person within the passageway or the direction of movement thereof cannot be detected at all or only by means of very complex means.
GB 2 175 348 A describes an automatically controlled passage barrier comprising a swivelling barrier and a scanning device, wherein the barrier is opened and afterwards automatically swivelled back into the closed position after detection of an object or a person by means of the scanning device. In order to assure that for example children who eventually stop their motion in the area of the barrier will not be hurt by the barrier that automatically closes after a determined time interval, the assembly comprises another scanning device which determines whether a person is present in the area of the barrier, whereby the barrier will be kept in its open position as long as the other scanning device detects no more person in the scanned area.
DE 9314 530 U1 describes a swivelling door for a passageway of persons comprising a swivelling door leaf and sensors connected therewith via control means. These sensors are adapted to determine whether a person is present in the passageway of persons, such that a warning signal can be emitted if for example the person wants to illegally leave a shop provided with such a passage barrier through the passage barrier. For this, the several sensors are arranged in such a way that they can detect the direction of movement of a person who moves in the passageway of persons, whereby the control means of the swivelling door can detect an illegal use of the passageway of persons.